Find the Index of the First Occurrence in a String

Given two strings needle and haystack, return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.

Constraints

1 <= haystack.length, needle.length <= 10⁴
haystack and needle consist of only lowercase English characters.

Example 1

Input: haystack = “sadbutsad”, needle = “sad”
Output: 0
Explanation: “sad” occurs at index 0 and 6. The first occurrence is at index 0, so we return 0.

Example 2

Input: haystack = “leetcode”, needle = “leeto”
Output: -1
Explanation: “leeto” did not occur in “leetcode”, so we return -1.

Solution

Use an inbuilt python function.

Since we have set a baseline lets try to code it :

class Solution:
    def strStr(self, haystack: str, needle: str) -> int:
        return haystack.find(needle)